BC Skill Update
Updates installed agent skills safely: version check, diff preview, backup, approval, data migration, and rollback. Use when updating or upgrading a skill, checking for newer versions, previewing what changed before applying, when a skill breaks, misbehaves, or loses data right after an update, when saved data or config must migrate across a version bump, when local edits to an installed skill would collide with the new version, or when bringing every skill or every agent's copy current. Not for installing new skills (skill-finder) or publishing skills you own (skill-publish).
Updates installed agent skills safely: version check, diff preview, backup, approval, data migration, and rollback.
As a process C 63/100 · Has gaps — weak spots: inputs and preconditions, consistency, running it twice
How to improve
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 0
✓ No critical or high findings
Files scanned: 9. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
name-formatname should be kebab-case (lowercase letters, digits, hyphens) - note
frontmatter-keyunknown frontmatter key "slug" - note
frontmatter-keyunknown frontmatter key "homepage" - note
frontmatter-keyunknown frontmatter key "changelog" - note
edit-residuethe text marks something as outdated (lines 97): check that old rules are not kept next to new ones — the full check reads the text for contradictions
Process rating: all ten parameters 63/100
- 0Inputs and preconditions. Does not say what the process needs to start
- 30Running it twice. 27 mutating operations with no state check
- 40Consistency. Frontmatter name (Skill Update) differs from the folder (skill-update)
- 50When it triggers. No condition that starts the skill
- 60Tools and files. Uses tools (web) that frontmatter does not declare
- 60Result and completion. Output format stated, no completion criterion
- 100Steps. 56 steps
- 100Failures and branches. 1 branches, has a failure section
- 100Execution cost. Instruction body is 3335 tokens
- 100Progress reporting. Reports progress
- medium Safety rules and hard prohibitions inside a skill: they belong in the system prompt, here they protect nothing
- low 14 top-level sections: this looks like several domains in one skill
- low The response is described with custom markup (5 tags): a typed call is more reliable
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +5Description has no quoted example phrases that should trigger the skill
- +1No license
- +2Single-language instructions
- +4Description says when NOT to use the skill
- +3Description length 583: enough signal without eating the budget
- +4Structure: 14 headings
- +3Step-by-step instructions: 56 items
- +3Output format is stated explicitly
- +4Has examples (3 code blocks)
Quality base 70; lint remarks subtract, signals add up to 100. Result: 83.